KEP MMI-7 Series Installation Instruction page 8

Ethernet Connections
Units equipped with the Ethernet port can be connected to Ethernet devices using
standard 10T CAT5 Ethernet cables. Routing may pass through Hubs and Servers as
needed to connect to the PLC.
The Ethernet port can also be used for MMI Master/Slave communications using the
same type of configurations.
Connect directly to PLC using 10T Crossover cable
Connect through Hub to PLC
Connecting through Server to PLC or Master
4.3 MMI TO MMI CONNECTIONS
The MMI supports a master - slave communications. One MMI is connected directly to the PLC and
configured as the Master. All the other MMIs are connected in series to it and are configured as Slaves. In
theory there is no limitation to the number of MMIs on a chain, however response time gradually
decreases when more than three MMIs are linked together. The MMI's are configured with the
EasyBuilder software to be the Master or a Slave.
Wiring between two MMIs
Case 1: Slave to Master, connecting PLC[RS232] directly to PC[RS-232]/PLC[RS485] combination
port.
Connect to SLAVE MMI PLC[RS-232] port
Cable has D-SUB Male end
2 TxD
3 RxD
5 GND
Case 2: Slave to Master, connecting PLC[RS232] to PC side of split download cable (MT5_PC) with use
of Male to Male Null Modem cable.
Connect to SLAVE MMI PLC[RS-232] port
Cable has D-SUB Male end
2 TxD
3 RxD
5 GND
Hub
Connect to MASTER MMI PC[RS-232] port
Cable has D-SUB Female end
8 RxD
7 TxD
5 GND
Shield
Connect to MT5_PC to MASTER MMI
PC[RS-232] port
Cable has D-SUB Male end
3 RxD
2 TxD
5 GND
Shield
8
PLC
PLC
Earth Ground
Earth Ground
Server